Conventionally, a probe holder with a thin plate shape on which multiple minute through holes are formed is embedded in a micro contactor to be used for a semiconductor test or a liquid crystal test in order to insert probes for electrically connecting a circuit structure of a test object with a circuit structure for sending a signal for the test. As the probe holder, a ceramic member with a free machining property (machinable ceramics) with which machining becomes possible is used (see Patent Literature 1, for example).